Where is the: "Hello dear customer? Dear customer?
It is not there because you are not a customer of mine. Perhaps you are a customer of avast, but that has nothing to do with trying to get a job they are offering. Those are two separate things.
Jana is not Avast employee, and it is not written on my message she is.
I never said that you claimed that she is a avast employee. I only said that is seems that she isn't.

It is very clear that you had contact with Jana and not with avast.
So if there are problems you need to take it up with her (or her employer) as avast has nothing to do with it.